In this paper, the colorimetric and fluorescent biosensors prepared from polyethylene glycol diacrylate (PEGDA)-based inverse opal photonic crystal (IOPC) decorated with graphene oxide (GO) (termed as GO-modified PEGDA-based IOPC) have been explored for simple and rapid semi-quantitative and quantitative detections of biomarker lipocaline-1 (LCN1) in tear at low level, respectively. We found that only after the concentration of GO () was sufficiently high to create a thin GO layer due to intermolecular interactions between neighboring GO molecules on the PEGDA surface, the red-shift of the reflection peak position (λ) became effective. This widening of the shift in λ became significant when GO-modified PEGDA-based IOPC was selectively attached with LCN1 via the immunoassay, because the attachment with LCN1 caused a reverse shift in λ. Correspondingly, the visualizable photonic color could vary in wider range depending on the concentration of LCN1 (), from orange color of blank solution to light blue color of solution containing LCN1 at of 0.06 mg/mL using = 2.5 mg/mL. For quantification, and enrichment time of LCN1 were optimized for getting the maximum fluorescence microscopy intensity. The diagram for the relationship between fluorescence intensity and showed various advantages of GO-modified PEGDA-based IOPC over non-GO-modified PEGDA-based IOPC. Those were higher fluorescence intensity, wider linear range and higher detection sensitivity. Thus, our results revealed potential applications of GO-modified PEGDA-based IOPC in screening patients with diabetic retinopathy (DR) in early stage.

中文翻译：

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氧化石墨烯装饰的水凝胶反蛋白石光子晶体改善比色和荧光响应，用于快速检测 lipocalin-1

本文探索了由氧化石墨烯（GO）修饰的基于聚乙二醇二丙烯酸酯（PEGDA）的反蛋白石光子晶体（IOPC）（称为GO修饰的基于PEGDA的IOPC）制备的比色和荧光生物传感器，用于简单和方便的检测。分别对泪液中低水平的生物标志物 lipocaline-1 (LCN1) 进行快速半定量和定量检测。我们发现，只有当 GO () 的浓度足够高，由于 PEGDA 表面上相邻 GO 分子之间的分子间相互作用而形成薄的 GO 层时，反射峰位置 (λ) 的红移才有效。当 GO 修饰的基于 PEGDA 的 IOPC 通过免疫测定选择性地与 LCN1 连接时，这种 λ 偏移的扩大变得显着，因为与 LCN1 的连接引起了 λ 的反向偏移。相应地，可视光子颜色可以在更宽的范围内变化，具体取决于 LCN1 () 的浓度，从空白溶液的橙色到含有 0.06 mg/mL LCN1 的溶液的浅蓝色（使用 = 2.5 mg/mL）。对于定量，LCN1 的富集时间进行了优化，以获得最大荧光显微镜强度。荧光强度之间的关系图显示了 GO 修饰的基于 PEGDA 的 IOPC 相对于非 GO 修饰的基于 PEGDA 的 IOPC 的各种优势。它们具有更高的荧光强度、更宽的线性范围和更高的检测灵敏度。因此，我们的结果揭示了基于 GO 修饰的 PEGDA 的 IOPC 在早期筛查糖尿病视网膜病变 (DR) 患者中的潜在应用。